Record-rotating mechanism



Oct. 26, 1937. M. A; LICH'II'EN 2,097,071

RECORD ROTATING MECHANISM Filed Nov. 27, 1935 4 Sheets-Sheet l INVENTOR Mal/ rice IQ. biwifen ATTORNEY Oct. 26, 1937. M LlcHTEN 2,097,071

RECORD ROTATING MECHANI SM Filed Nov. 27, 1935 4 Sheets-Sheet 2 56L L78 INVENTOR ATTORNEY Oct. 26, 1937. M. A. LICHTEN 2,097,071

RECORD ROTATING MECHANISM Filed Nov. 27, 1935 4 Sheets-Sheet 3 INVENTOR mall/wee J? Lie/472% m ATTORNEY M. A. LICHTEN RECORD ROTATING MECHANISM Filed NOV. 27, 1935 4 Sheets-Sheet 4 INVENTOR marinas/7.1mm): BY

WMMA M ATTORNEY Patented Oct. 26, 1937 PATENT OFFICE 2.097.071 RECORD-ROTATING mzcnsmsm Maurice A. Lichten, Long Island City, N. Y., as-

signor to Fidelitone Records, Inc., New York, N. Y., a corporation of New York Application November 27, 1935, Serial No; 51,776

25 Claims.

This invention relates to the recording and reproduction of sound, and more particularly to apparatus for effecting relative movement of the parts during such recording and reproduction, 5 and to correlated improvements and discoveries appertaining thereto.

This application is a continuation-in-part of my co-pending application, Serial filed February 2, 1933.

An object of the invention is the provision of means whereby a sound record may be rotated with a high degree of smoothness and accuracy.

A further object is the provis ion of means for eiiectuating a smooth and accurate movement of a portion utilized in the recording or reproduction of sound, which means is simple of construction and economical to manufacture and use, and which may be readily operated and controlled.

Other objects are directed to various improved features of con ing means for a device for the re duction of sound.

the provision of struction in driv cording or repro- Still another object is the provision of an improved friction drive unit adapted to be associated with a rotatable member.

An additional object is the provision of an improved method for the provision of a friction drive unit adapted to be removably disposed on a rotatable member.

Other objects of the invention will in part be obvious and will in part appear h ereinafter.

The invention accordingly comprises the features of construction, combinations of elements and arrangement of parts, and

the several steps and the relation and order of one or more of such steps with respect to each of the others thereof, all of which will be exemplified hereinafter and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed desc ription taken in connection with the accompanying drawings, in

which:

Figure 1 is a side view of oneform of apparatus embodying the invention;

Fig. 2 is a vertical section thereof;

tus embodying the invention;

Fig. 6 is a vertical sectional vi t-G of Fig. 5;

ew along the line F18. "I is a similar view of a modified form of apparatus;

Fig. 8 is a perspective view on a larger scale of the friction drive unit shown in Fig. '7;

Figs. 9, 10, 11 and 12 'are perspective views show- 1 ing various stages in a manner of formation of units such as shown in Fig. 8, in accordance with the invention; Fig. 9 showing a metallic cylindrical member; Fig.- 10, this member with a layer of additional material thereon; Fig. 11, this member 1 with a yieldable friction layer thereon; and Fig. 12, this member with oneunit cut from it;

Fig. 13 is an enlarged detail side view of a portion of a machine such as shown in Fig. '1 showing a modified form of construction; and V 1 Fig. 14 is a vertical sectional view along the line "-14 of Fig. 13.

For the purposes of facility of expression the term sound" is used herein to include all impulses in the recording and reproduction of which 2 problems similar to those present in the recording and reproduction of sound impulses are involved, and the term sound recor is used herein in its broad sense to designate record blanks-adapted to have sound vibrations or other impulses 2, recorded thereon and also record members bearing such recordings.

In the rotation of sound records, and particularly in the rotation of flexible sound records for the recording of impulses thereon, it is important 31 that tendencies toward vibrations be minimized, that variations in the rotative movement be as smooth and accurate as possible; and, especially in recording, that both the rotation of the record and the movement of a stylus across a record be 31 eflected with smoothness and accuracy. Diiliculties have been encountered in previous efforts to provide driving means which arefree from jerkiness or other variations in movement; and which, at the same time, do not impart: ,undesirable vibra- 4i tions to the operative portions. of the device.

' With the foregoing and other considerations in view, there may be provided in accordance with the invention a motor drive whereby a smooth and accurate movement of the driven parts is 4 obtained and vibration avoided and whereby greatly improved results are obtained.

Since driving means embodying the invention preferably comprise cooperating friction drive portions. at least one of which is yieldable, and 50 since yieldable members of this nature need to be replaced at fairly frequent intervals, the invention further contemplates the provision of a replaceable friction drive unit which is particularly adapted for use in apparatus embodying mechanism adapted to be carried on a base I in the form of a supporting plate which may be mounted within any suitable type of cabinet if V desired. From this plate there depend electric motors 2, two of which, spaced 120 apart in the present instance, are provided to obtain a particularly high degree of smoothness of operation. By means of fastening devices 3 each motor is yieldably carried by a pair of bowed springs 4 mounted on members 5 passing thru yleldable bushings 6 which may be formed of rubber and which are carried on the plate I. The shaft I of each motor carries at its free end a driving roller 8 which may be formed of resilient material, such as rubber, and which, due to the offcenter support of the motor from the member 5 is adapted, due to the weight of the motor, to bear upon an annular friction drive portion secured to the inner edge of a depending flange In on a fly-wheel II. The springs serve to assure a flrm, effective and smooth engagement of the roller with the portion 8. The annular portion 8 may be formed of rubber or other suitable material. The fly-wheel ll rotates beneath a record-supporting table I2, which, in accordance with my said application, Serial. No. 654,782, is stationary and is provided witha resilient supporting surface. The table I2 is formed in the present instance with a depending flange l3 secured to the base I by fastening devices l4 so that the fly-wheel is enclosed in a chamber l5 between the base and the stationary support. The upper portion of the support "comprises, in the present instance, a layer of sponge rubber l6 and a layer of felt I! on which a sound record, such for instance, as the flexible record exemplifled at It, is adapted to rest. The record may be rotated from the fly-wheel by a coupling ll carryingpins which extend into apertures 2| in the fly-wheel. From the upper surfaces of the coupling, pins 22 adapted to be received by apertures 23 in the'recordextend upwardly, and the coupling member I9 is also provided with the usual center pin 24 adapted to extend thru an aperture 25 in the record. In order to permit the stylus carrier to be driven from the motors 2,

the lily-wheel and coupling are provided with a tapered opening 26 adapted'to closely engage a tapered portion 21 of a shaft 28 journalled in a bearing 29 and having its lower end resting on a ball 30 which can be vertically adjusted by means of a set screw 3| provided with a lock nut 32. This bearing 29 may be carried from the base I in any desired manner. The shaft 28 is provided with a worm 33 which is adapted to mesh with a worm gear 34 from which a styluscarrying arm may be driven across a record, all as fully disclosed in said co-pending application, Serial No. 654,782. The coupling I! is recessed at 35 to receive the free end of the shaft 22.

The mounting 6-6 is connected to the springs 4 at such a point that the motors are carried offcenter, so that the rollers will be thrust by the weight of the motor against the annular portion 9 in such manner that the driving engagement will be in a direction radial to the axis of rotation of the fly-wheel,horizontally, in the present in-- 'stance,-so that. even though the motor shaft shifts, the speed of the fly-wheel and consequently of the record, will not be substantially altered.

I Because of the yieldability of the mounting 0 and also of the springs 4, the weight of the motor presses the roller eflectively against the annular drive portion.

The height of the fly-wheel may be varied by the adjustment of the set screw 3| which effects a raising or lowering of the shaft 28 and of the members carried thereby.

In the present exempllflcation, both of the motors are adapted to be in circuit at the same time. By the provision of a pair of motors, each of these acts to control the movement imparted to the fly-wheel by the other, so that a balanced, smooth drive of the fly-wheel, and hence of the record, and also of connected parts, such as a stylus carrier, may be obtained. By the mounting of these motors at 120, or in some other position where they are not directly opposed to each other, tendencies toward a periodicity of variation characteristics is minimized.

In the form of construction exemplified in Figs. 5 and 6, there is provided a recording machine comprising a main support 40 on which there is rotatably mounted a fly-wheel 4| on the shaft 42 of which is carried a rotatable head or coupling 43. From the head 43 there extends a center pin 44 and driving pins 4|. These pins are adapted to enter openings in a flexible record 40 and to revolve the same on a rotatable stationary support, as claimed in my said application, Serial No. 654,782. This support comprises a plate 41 carrying a layer of rubber 41a and a layer of felt 41b, and is mounted thru the medium of rubber inserts 48 on posts 49 extending from the plate 40. In order to engrave a record rotating on said support, there may be employed means such as exemplified in my copending application, Serial No. 44,138, flied October 9,1935, comprising a stylus ll carried by a sound head 5| which is pivotally mounted on an arm 52 slidably connected with a bracket II. From the bracket 53 there extends an arm Ila carrying an adjustable screw "b from which an elastic band 530 extends to the sound head II to elastically support the same. The bracket l2 is'slidably and pivotally mounted on a lateral rod 54 and isformed with a threaded portion II adapted to engage a worm on a rotatable shaft ll. The rod 54 and the shaft are mounted in frame members 51 and 58 and the shaft 56 carries at its outer end one of a plurality of different sized pulleys 59a, 59b, and We, connected bya belt 6| to one of a plurality of cooperating pulleys Ila, Nb, and Ole, carried on a shaft 62. By shifting the belt from one pair of pulleys to another the spacing of the grooves cut in a record may be readily varied. The shaft 2 carries a worm l2 meshing with a worm gear 64 on the shaft 42. In the present instance the worm on the shaft I. only extends from the center of the record to the periphery in one direction. The fly-wheel 4| and the worm 64 are secured to the shaft 42 by means of set screws 64a and 4b, upon the loosening of which the shaft may be slid upwardly to permit the fly-wheel to be moved laterally of the machine so that the bearing portion I! may be replaced when deteriorated or worn.

In accordance with the invention there is provided at the periphery of the fly-wheel an annular friction drive portion I having a vertical engaging surface; and motors I and a are hung off-center from the plate 4|, so that rollers 61 and 68 respectively on their shafts wfll engage the annular drive portion in a direction which isradialtotheaxisofrotationofthefly-wheekportion 65; the mounting means for a motor being of a yieldable nature and comprising fastening members 69 extending from one side of the motor casing and carried by rubber inserts iii in a plate ll secured to the plate 48. Preferably one or the other 'ofthe drive means (i5,

or 61-88, or both, are formed of resilient material, the annular band 85 being formed .of rubher in the exemplified construction, and the rollers 61 and 68having knurled micarta surfaces In the present instance it is contemplated that only one of the motors will serve as the driving meansat any given time; the motors being arranged, in accordance with. the invention, to drive the fiy-wheel at different speeds, so that records rotated thru the mediumof the fly-wheel may be turned fast or slow, as may be desired in any particular case, as for instance when a small record or a large record, respectively, is being rotated. In certain instances both rollers may be maintained in engagement with the annular drive means, although only-one motor will be energized, the other motor serving to overcome certain unbalanced conditions or lack of smoothness of rotation sometimes occurring. In other instances, one or the other of the rollers will be record will be'rotated more rapidly than when the motor 86a. is in circuit than when the motor 66 is in circuit. In' order to energize one or the other of the motors as desired, there are provided means comprising conductors I8 and 18, a switch 14, leads l5 and I6 to the motor 68a, and leads I1 and 18 to the motor 66.

Since the annular drive portion 85 is compressible, the exact speed at which the fiy-wheel is driven will depend upon the pressure exerted by that motor which is in circuit, and in order to make this speed exactly proper for the desired type of recording, there is provided an adjustable means whereby the pressure of each roller against the annular drive. portion may be controlled. In the present instance, this means comprises screws 19 each threaded thru one of the parts II and desirable sound efl'ects, particularly where the stylus vibrates laterally, as in the usual case.

In the embodiment of theinvention shown in Fig. '7, the arrangement is similar to that of Figs. 5 and 6, and the parts are designated by similar reference numerals, except that the motor 68 is shown swung inwardly with its ing 12 held in the bend of the spring 12a, and with its roller 81 out of engagement; and except that the fiy-wheel .ll

is replaced by a fiy-wheel I d, on theperiphery of which there is provided. a removable friction drive unit 8| carrying a friction drive portion 68d of the same general character as the friction drive portion 85.

As will be apparent, the unit 8! is removably mounted on the periphery of the fiy-wheel d, so as to'permit the removal 'of the fly-wheel or of the unit 8I,.so that one unit may be removed from the fiy-wheel and a similar unit fitted over it. The fiy-wheel is formed with projections 82, and the unit 8| with cooperating notches 83 adapted to be received by those projections so that the drive unit and the fly-wheel will rotate together. By the provision of a removable unit of this nature, the friction drive portion may be readily replaced by a similar portion when it has undesirably deteriorated or worn down. Due to the removability of the fiy-wheel, upon the loosening of the set screws 64a and 64b and the raising ,of the shaft 42 as above indicated, a. drive unit 8| may be readily removed from the fiy-wheel and replaced by a similar unit. a

While removable units of any of a variety of suitable types may. be utilized, the invention in certain of its aspects contemplates the provision of a friction drive unit of a simple andhighly effective character, such as exemplified in Fig. '1' and shown in detail in Fig. 8. This unit comprises a metallic annulus 84 having a layer 85 of hard rubber secured thereto and a facing layer 88 of soft rubber adhering firmly to the hard rubber and providing the friction drive portion.

In forming the drive units, such as shown at 8 I, in accordance with the invention, there is provided a metallic cylinder 81 as shownin Fig. 9. On this cylinder there is vulcanized a layer 88 of hard rubber, as shown inFlg. 10, the hard rubber adhering firmly to the cylinder. Thereupon a layer of yieldable soft rubber 88 is vulcanized upon the hard rubber layer. 88 and the surface of the soft rubber is smoothed oil to a uniform circumference, as by a grinding wheel 80, as shown in Fig. 11, which may be kept wet, and may be shifted along the surface of the soft rubber thru a bearing 8|. Thereupon the cylindrical assembly thus formed is cut transversely, as along lines 82, to provide units 88 in which notches 83 may be suitably formed; if desired, to provide friction driving units such as shown in Fig. 8.

In Figs. Band 14 there is exemplified a construction which is similar to that shownin Fig. 7 and wherein the parts not appearing in the drawing and wherein all of the parts except those having to do with the motor mounting are similar to those of the construction of Fig. I, and so far as they appear in the drawings are designated by similar reference numerals In the present exemplification, each of the motors 66 and 68a are supported by means particularly exemplified in connection with the motor 88. This means com-- prises a plate He supported on the plate 40 thru the medium of rubber inserts 84. Thru openings 85 inthe plate He there extend supporting posts 88e having heads 96 which are carrled on coil springs 81 which serve to yieldably and resiliently hold the posts on the plate He in the openings 85 and about the posts there are disposed yieldable rubber collars 88 which are adapted to permit the posts 88:: to swing during the adjustment of. the motor. At their lower ends the posts carry horizontal extensions 88a having horizontal slots 88 therein thru which there extend screws I88 secured to the casing of the motor 88. By the adjustment of the screws i!) inwardly or outwardly along the slots 99 a motor may be shifted so that its roller 61 or 68, as the case may be, may be aligned to bear upon the drive portion 6511 in different amounts, but with equal pressure thruout the vertical extent of the rollers. By such means the motors are spring-supported, as are the motors 2, so as to assure a particularly effective engagement of the rollers with the annular friction drive portion 65d. Furthermore the transmission of vibration to the record support and other members is substantially eliminated, and a simple and highly effective motor mounting provided.

It will thus be seen that, in accordance with the invention, there may be provided simple, effective, and readily adjustable means whereby sound records may be rotated with a high degree of smoothness and accuracy under a variety of conditions, and a variety of advantageous results secured.

Since certain changes in the construction set forth and in carrying out the above method and different embodiments of the invention may be made without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. Apparatus for the recording or reproduction of sound comprising a rotatable member, an annular friction drive portion on the rotatable member, a motor carrying a cooperating friction drive portion on its shaft. and means includin yieldable supporting means for mounting said motor off-center at such a point that the weight of the motor will cause it to tilt to press the drive portion on its shaft in driving engagement with said annular drive portion, said drive portions being so arranged that the second mentioned drive portion will bear toward or away from the axis of rotation of the rotatable member.

2. Apparatus for the recording or reproduction of sound comprising a rotatable member, an annular friction drive portion on the rotatable member, a motor carrying a cooperating friction drive portion on its shaft, and means including yieldable supporting means for mounting said motor off-center at such a point that the weight of'the motor will cause it to tilt to press the drive portion on its shaft in driving engagement with said annular drive portion,said drive portions being so arranged that the second mentioned drive portion will bear toward or away from the axis of rotation of the rotatable member, at least one of said drive portions being resilient.

3. Apparatus for the recording or reproduction of sound comprising a rotatable member, an annular friction drive portion on the rotatable member, a motor carrying a cooperating friction drive portion on its shaft, means including yieldable supporting means for mounting said motoroff-center at such a point that the weight of the motor will cause it to tilt to press the drive portion on its shaft in driving engagement with said annular drive portion, said drive portions being so arranged that the second mentioned drive. portion will bear toward or away from the axis of rotation of the rotatable member, and means to control the pressure of said drive portions against each other.

4. Apparatus for the recording or reproduction of sound comprising a rotatable member, an annular friction drive portion onthe rotatable member, a motor carrying a cooperating friction drive portion on its shaft, and means including spring means for mounting said motor off-center at such a point that the weight of the motor will cause it.to tilt to press the drive portion on its shaft in driving engagement with said annular drive portion, said drive portions being so arranged that the second mentioned drive portion will bear toward or away from the axis of rotation of the rotatable member.

5. Apparatus for the recording or reproduction of sound comprising a rotatable member, an annular friction drive portion on the rotatable member, a motor carrying a cooperating friction drive portion on its shaft, means including yields able supporting means for mounting said motor, and means including said mounting means to cause the friction drive portion on the motor shaft to be pressed in driving engagement with said annular drive portion, said drive portions being constructed and arranged to maintain the distances between each of their axes and the, position of driving engagement constant whereby a uniform speed relation is maintained between said motor and said rotatable member irrespective of the longitudinal position of the motor drive shaft. I

6. Apparatus for the recording or reproduction of sound comprising a rotatable member, a motor, an annular friction drive portion on the rotatable member, a cooperating friction drive portion on the shaft of the motor, supporting means, a yieldable portion on said supporting means, and means to support said motor dependently from said yieldable portion at a point at one side of the center of gravity of the motor, the said drive portions being so arranged that the drive portion 7 perpendicular to the axis of the rotatable memher.

7. Apparatus for the recording or reproduction of sound comprising a rotatable member, a motor, an annular friction drive portion on the rotatable member, a cooperating friction drive portion on the shaft of the motor, supporting means, a yieldable portion on said supporting means, means to support said motor dependently from said yieldable portion at a point at one side of the center of gravity of the motor, the said drive portions being so arranged that the drive portion on the motor shaft will bear against the drive portion on the rotatable member in a direction perpendicular to the axis of the rotatable member, at least one of said drive portions being resilient, and means to control the pressure of the drive portion on the motor shaft against the drive portion on the rotatable member.

8. Apparatus for the record ng of sound comprising an annular member, supporting means, a yieldable portion on said supporting means, means to support a motor off-center from said yieldable portion, an annular friction drive portion on the annular member, a cooperating drive portion on the shaft of the motor, said motor and said annular member being so disposed that the drive portion on the motor shaft will bear against the drive portion on the annular member in a direction perpendicular to the axis of the annular member, record-rotating means adapted to turn with said annular member, a stylus carrier, and means to drive said stylus carrier from said annular member.

9. Apparatus for the recording or reproduction of sound comprising a rotatable member, an anmember, a motor carrying a cooperating friction drive portion on its shaft, said. motor being mounted off-center at such a point that the weight of the motor will cause it to tilt to press the drive portion on its shaft in driving engagement with said annular drive portion, said drive portions being so arranged that the second menannular friction drive portion on the rotatable member, a plurality of motors each carrying on its shaft a friction drive portion adapted to cooperate with the friction drive portion on the rotatable member, and means including yieldable supporting means for mounting each motor oilcenter at such a point that the weight of the motor will cause it to tilt to press the drive portion on its shaft in driving engagement with said annular drive portion, said drive portions being so arranged that the drive portions on the motor shafts will bear toward or away from the axis of rotation of the rotatable member.

11. Apparatus for the recording or reproduction of sound, comprising a rotatable member and a plurality of motors each carrying a drive portion adapted to engage said rotatable member to drive the same, said motors being adapted to be energized simultaneously.

12. Apparatus for the recording or reproduction of sound, comprising a rotatable member and a plurality of motorsv each carrying a drive portion adapted to engage said rotatable member to drive the same, each of said motors being adapted to drive said rotatable member at a different speed, and means to energize one or another of said motors as desired.

13. Apparatus-for the recording or reproduction of sound, comprising a rotatable member and a plurality of motors each carrying a drive portion adapted to engage said rotatable member to drive the same, each of said motors being adapted to drive said rotatable member at a different speed, and means to prevent the engagement of the drive portion of any of said motors with said rotatable member so that the drive portion of only a desired one of said motors will be operative to drive the rotatable member.

14. Apparatus for'the recording or reproduc: tion of sound comprising a rotatable member, an annular friction drive portion on the rotatable member, a plurality of motors each carrying on its shaft a friction drive portion adapted to cooperate with the friction drive portion on the rotatable member, means including yieldable supporting means for mounting each motor offcenter at such a point that the weight of the motor will cause it to tilt to press the drive portion on its shaft in driving engagement with said annular drive portion, said drive portions being so arranged that the drive portions on the motor shafts will bear toward or away from the axis of rotation of the rotatable member, and means to energize said motors at the same time, said motors being well spaced but asymmetrically disposed with respect to said rotatable member.

15. Apparatus for recording sound, comprising means to rotate-a record blank, a stylus carrier, means driven from said rotating means to move said stylus carrier transversely of a record blank during the rotation thereof by said rotating means, and a driving connection between said rotating means and said stylus carrier adapted -for adjustment to enable the speed of transverse movement of the stylus carrier to be varied.

16. Apparatus for the recording or reproduction of sound comprising a rotatable member, an annular friction drive unit re'movably mounted on said rotatable member and providing an annular resilient friction drive portion, a motor carrying a cooperating friction drive portion on its shaft, means for mounting said motor, and means including said mounting means to cause the friction drive portion on the motor shaft to be pressed in driving engagement with said annular drive portion.

17. Apparatus for recording sound comprising a rotatable member, an annular friction drive unit removably mounted on said rotatable member and comprising a rigid annulus and a resilient annular friction drive portion, a plurality of motors each carrying on its shaft a friction drive portion adapted to cooperate with the friction drive portion on the rotatable member, means including yieldabie supporting means for mounting each motor off-center at such a point that the weight of the motor will cause it to tilt to press the drive portion on its shaft in driving engagement with said annular drive portion, said drive portions being so arranged that the direction of driving engagement will be radial to the axis of rotation of the rotatable member.

18. A friction drive unit adapted to be removably mounted on a rotatable member and comprising a metallic annulus having a layer of soft rubber on one side thereof and secured thereto by an intermediate layer of hard rubber adherent to both the metal and the soft rubber.

19. A friction drive unit comprising ametallic annulus adapted to be removably fitted upon a cylindrical surface of a rotatable member, a layer of hard rubber vulcanized on said metallic annulus and a layer of soft rubber vulcanized on said layer of hard rubber and providing a yieldable engageable surface, said unit being formed with means providing a driving connection with the rotatable-member.

20. The method of forming friction drive units which comprises vulcanizing rubber on a metal cylinder to provide a layer of hard rubber thereon, .vulcanizing rubber on the hard rubber layer to provide asurface layer of soft rubber thereon, smoothing the surface of the soft rubber layer, and dividing the cylinder transversely into annular driving units.

21. Apparatus for the recording or reproduction of sound comprising a rotatable member, an annular friction-drive portion on the rotatable member, a motor carrying a cooperating friction-drive portion on its shaft, and means including yieldable supporting means for mounting said motor off-center at such a point that the weight of the motor will cause it to tilt to press the drive portion on its shaft in driving engagement with said annular drive portion, at least one of said drive portions having an elongated driving surface which is parallel to its axis of rotation.

22. Apparatus for the recording or reproduction of sound comprising a rotatable member, an annular friction-drive portion on the rotatable member, a motor carrying a cooperating frictiondrive portion on its shaft, and means including yieldable supporting means for mounting said motor off-center at such a point that the weight of the motor will cause it to tilt to press the drive portion on its shaft in driving engagement witbaaidannuiardriveportiomtheaxeaoiaaid driveportionawhen tbeaameareinemagement, being substantially parallel.

28. Apparatus for the recording or reproduetion oi sound oomprisingabaae.arotatable member mounted on said base, an annular frictiondrive portion on the rotatable a motor carrying a cooperating friction-drive portion on itrsbaitabouaing ioraaidmotoxzmeane including yieldable supporting mean: for mountingsaidmotorofl-oenteratruchapointthatthe weigbtottbemotorwilloauaeittotilttopreas thedriveportiononitaabaitindrivingengagement with aaid annular driveportion, and meana tooontroltbepreasureotsaiddriveportiona againateachotbenaaidmeanacompriaingalip on said motor housing and an adjustable element mounted'inaaidbaleand laid lip.

iLApparatuatortbe renordlmorreproduoumdmdmtmbtmmm' apiin-alityot motoraeaohoarryingadriveportion adapted to engage said rotatable member todrivetbeaame,meanaiorurgingaaiddrive portions into engagement with said rotatable I tion of sound comprising a rotatable member, a 10 laminated annular friction-drive unit mounted on said rotatable member and providing an annular resilient friction-drive portion. and a motor, carrying a courier! friction-drive portion on its shalt, mounted for causing frictional l6 driving engagement of said friction-drive por- 

